Crankcase breather cap



March 9, 1937. H. e. KAMRATH 2,073,156

CRANKCASE BREATHER CAP Filed Feb. 25, 1935 Patented Mar. 9, 1937 UNlTED STATES CRANKCASE BREATHER CAP Herbert G. Kamrath, Flint, Mich., assignor to General Motors Corporation, Flint, Mich., a v corporation of Delaware Application February 25, 1935, Serial No. 8,046

4 Claims.

This invention relates to closure members, and more specifically to Ventilating breather caps for crankcase ventilation on motor cars.

It is an object of my invention to provide a breather cap which will eiiciently lter the air flowing into the crankcase of a motor upon a volumetric change in the crankcase.

It is 4a further object of my invention to provide a breather cap which will act as a condenser for oil vapors flowing from the crankcase.

A still further object is to provide a breather cap to fulil the above requirements, and yet will be simple to construct and easily removed and attached to the breather pipe.

With these and other objects in View which will be evident in the light of the following disclosure, my invention resides in the construction as set forth in the specication and claims and illustrated in the accompanying drawing, in which:

Figure 1 shows a vertical section through an internal combustion engine with my breather cap attached.

Figure 2 is a vertical section through the breather cap taken on the line 2--2 of Figure 3.

Figure 8 is a bottom plan view of the device.

Figure 4 is a vertical section through the centr-al portion of the cap only on line 4-4 of Figure 3 at right angles to the section shown in Figure 2.

A conventional internal combustion engine 2 has a cylinder 4, piston 5, connecting rod 8, crankshaft ID and crankcase l2. A breather pipe I4 extends from one side of the crankcase and over the end fits the breather cap i6 which is the subject of my invention.

The cap per se comprises a central cylindrical member or tube i8 of a diameter to iit snugly over the end of the pipe I4 and having near its upper end a series of openings 29 spaced throughout the circumference. An outer shell 22 which is cup-shaped has a pressed out portion 24 in its base which lits over the top o the member i8 when the cup is inverted over the cylinder. The

' lower rim of the shell is spaced from the cylinder by an annular ring 26, the two edges of which are lianged as at 2B and 30, the inner ange 2B being secured to the cylinder by spot welding, and the outer iiange 30 crimped up -around the edge 50 of the shell. This annular ring has a series of circular holes 32 throughout its circumference, through which the air may flow. The outer shell 22 also has a series of louvres 34 in its lower portion for air iiow.

55 Inside the cylindrical member i8 about midway between its two ends is secured a bracket 36 which extends across the cylinder and towhich is secured by a rivet a spring clip 38 shaped so that the legs press against the inside of the pipe it when the cap is in place to hold it securely.

'The interior of the cylinder above the bracket 38 is lled with copper mesh 4i) or other suitable pervious material, and the chamber formed be tween the cylinder and the outer shell is also iilled with a similar material 42.

From this construction, it is evident upon a volume change in the crankcase, that the air may enter either through the louvres 34 or through the circular openings 32 in the annular ring 2e, then it passes up through the filtering material 42, through the openings 2S and down through the filter material lil to the crankcase. There is a large intake area pro-vided which prevents plugging up. Also there is abundant surface for iiltering the dirt particles from the air as it goes into the crankcase. In case there is an increase in volume of the oil or oil vapor in the crankcase, and there is a tendency of the vapor to flow from the crankcase, the cil vapor will pass up into the pervious material and will condense, some air passing out of the cap and the oil returning to the orankcase. Some oil Will, of course, be carried out into the outer chamber and this will wet the iilter material 42 which will increase its efliciency as a filter and if suicient oil passes into the chamber it will run down through the material 42 and wash oi the dirt.

I claim: y

1. A breather cap comprising, a central tube, a larger one piece cup-shaped shell having the closed end thereof secured to one end of the tube and the sides thereof extending around the tube along its length, openings in the side of the tube adjacent the attachment to the shell, a spacing member secured to the tube and the free end of the shell, louvres in the lower end of the shell, openings in the spacing member, a bracket secured across the tube substantially midway between its ends and a spring clip secured to the bracket for assisting in securing the cap to a breather pipe.

2. A breather cap comprising a one piece cup shaped shell having a depression in the closed end and louvres near the free end, a central tube having openings in the walls thereof near one end, said end extending into said depression, a spacing member having openings therein, said member being secured to the tube and the free end of the shell, a bracket secured across the tube substantially midway between its ends, pervious material in the tube above said bracket and in the space between said tube and said shell, and a spring clip secured to the bracket for assisting in securing the cap to a breather pipe.

3. A breather cap comprising a one piece cupshaped shell having louvres near the free end thereof and a depression in the closed end, a central tube within said cup-shaped member having openings in the walls near one end, said end extending into said depression, a spacing member secured to said tube near the opposite end thereof and to the free end of said cupshaped member, a bracket secured across the tube substantially midway between its ends, and pervious material in said tube above the bracket and in the space between said tube and the cup-shaped member.

4. A breather cap comprising a one piece cupshaped shell having a depression in the closed end thereof, a central tube within said shell having openings in the Walls thereof adjacent one end, said tube end extending into said depression, a spacer member xed to the free end of said shell and to the tube near the end opposite the end in said depression, a bracket secured across the tube substantially midway between the ends and pervious material in said tube above said bracket and in the space between said tube and said cup-shaped member, there being openings in the spacer member and adjacent shell Wall to permit air to flow within the structure.

HERBERT G. KAMRATH. 

